1. Field of the Invention
The present invention relates to pressure-connection terminals for electrical connectors.
2. Description of the Related Art
FIG. 4 shows a modular connector of this type. A terminal slot 52 is provided at an upper right-hand corner of a housing 51. A terminal 53 made of a metal sheet is provided in the terminal slot 52.
As FIGS. 5(A) and 5(B) show, the terminal 53 has a T-shaped, flat terminal base 54 with a head portion 54A and a pressure-connection section 55 extending downwardly from the terminal base 54. A pair of stop shoulders 54B are provided on the lower edges of the head portion 54A. A terminal recess 56 is provided in the pressure-connection section 55 to form a pair of blade members. The pressure-connection section 55 is gradually thinned to the front end in the form of a blade. See FIG. 5(B). A pair of temporary latch members 57 with a rounded projection are provided on the side edges opposite to the terminal recess 56. A pair of permanent latch members 58 are provided on side edges of the terminal base 54. The distance between the tips of permanent latch members 58 is made slightly greater than the distance between the tips of temporary latch members 57 so that the permanent latch members 58 extend outwardly more than the temporary latch members 57.
As FIG. 5(B) shows, the pressure-connection blade members 55 are displaced in opposite directions such that the distance of the displacement (d) is smaller than the diameter of a cable (C).
In FIG. 4, the housing 51 is made from an insulating material so as to provide a plurality of terminal slots 52 which are arranged in parallel to the sheet. Each terminal slot 52 has a press-insertion section 52A for receiving the portion below the stop shoulders 54B and a pair of abutment surfaces 59 for supporting the stop shoulders 54B. The width of the pressure-insertion section 52A is slightly smaller than the distance between the tips of the temporary latch members 57.
A plurality of cable insertion holes 60 are provided in the housing 51 for receiving the cables (C) and communicate with the pressure-insertion slots 52A.
A plastic member 61 is provided in a rear recess 60A of the housing 51 in a direction perpendicular to the cables (C) in the cable insertion holes 60 to form a pair of thin wall portions 62 on opposite sides. A resilient lock arm 63 extends rearwardly from the front portion of the housing 51.
In this conventional connector, the terminal 53 is pushed into the terminal slot 52 until the temporary latch member 57 cuts into the side wall of the pressure-insertion section 52A so that the terminal 53 is held by the housing 51. In this point, the pressure-connection section 55 does not enter the cable insertion hole 60.
The cable (C) is then inserted into the cable insertion hole 60, and the terminal 53 is further depressed. The stop edges 54B of the terminal 53 abut against the stop shoulders 59 of the housing to thereby prevent further insertion of the terminal 53, when the pressure-connection blade members 55 pierce into the cable (C). The pressure-connection blade members 55 penetrate into the core wire (C1) while bending it between them. Also, see FIG. 5(B).
Then, the plastic member 61 is depressed and plastically deformed with a tool so as to crash and hold the cable (C) in place.
However, the following improvements are demanded for the conventional terminal of FIGS. 4 and 5.
While the temporary latch members 57 are pushed into the pressure-insertion slot 52A, they cut the side walls of the pressure-insertion slot 52A. When the permanent latch members 57, which are located in different planes from the temporary latch members 57, are pressed-in, they cut the walls at locations slightly different from the cut locations of the temporary latch members 57. Consequently, the force necessary for the pressure-insertion of the permanent latch members becomes large. This large impact causes damage to the walls of the pressure-insertion section 52A where the permanent latch members 58 engage the pressure-insertion section 52A, resulting in the reduced holding power of the terminal.
In addition, since the terminal recess 56 is relatively shallow, a thick cable cannot be bent satisfactorily between the pressure-connection blade members 55.